Recent market trend increasingly requires a miniaturization of solid-state image pickup devices which include CCD (Charge Coupled Device) or CMOS (Complementary Metal Oxide Semiconductor) for using in digital cameras and cell phones. Thus recently, CSP (Chip Size Package), the size of which is generally the same with that of a solid-state image pickup element chip, is becoming a standard type rather than the conventional large package system in which an entire solid-state image pickup element chip is hermetically sealed into a package of ceramics or the like.
In this context, a method has been proposed, which including: adhering a wafer (semiconductor substrate), in which a plurality of light receiving sections for solid-state image pickup elements are formed with separation grooves being provided between the adjacent light receiving sections, and a glass cover plate, which is a transparent glass sheet having spacer sections formed thereon at positions surrounding each light receiving section, to each other at the positions of the spacers so as to form spaces between the glass cover plate and the wafer; polishing the glass cover plate and the wafer by chemical mechanical polishing to the points to reach the separation grooves; and separating individual solid-state image pickup devices.
The separation grooves of the glass cover plate has a width required to expose a pad surface at outside of the light receiving sections of the solid-state image pickup elements to be provided with wiring from the exterior (for example, see Japanese Patent Application Laid-Open No. 2004-006834).